With global warming, the world isn’t just getting hotter – it’s getting stickier, due to humidity. And people are to blame, according to a study based on computer models published Thursday.

The amount of moisture in the air near Earth’s surface rose 2.2 percent in less than three decades, the researchers report in a study appearing in the journal Nature.

“This humidity change is an important contribution to heat stress in humans as a result of global warming,” said Nathan Gillett of the University of East Anglia in the United Kingdom, a co-author of the study.

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The finding isn’t surprising to climate scientists. Physics dictates that warmer air can hold more moisture. But Gillett’s study shows that the increase in humidity already is significant and can be attributed to gas emissions from the burning of fossil fuels.

To show that this is man-made, Gillett ran computer models to simulate past climate conditions and studied what would happen to humidity if there were no man-made greenhouse gases. It didn’t match reality.

He looked at what would happen from just man-made greenhouse gases. That didn’t match either. Then he looked at the combination of natural conditions and greenhouse gases. The results were nearly identical to the year-by-year increases in humidity.

Gillett’s study followed another last month that used the same technique to show that moisture above the world’s oceans increased and that it bore the “fingerprint” of being caused by man-made global warming.

So yeah, not only is it getting warmer… it’s getting muggier. Wonderful.

On the plus side, maybe this will discourage the people who think warmer weather sounds like a great idea.